Baby diapers or incontinence diapers designed for a single use have closing systems that permit rapid and simple closing and opening of the diaper, and have attachment parts mounted on the side of the diaper. The attachment parts are in the form of a band or in a wide form called diaper tabs. Support parts connected to the attachment parts comprise projecting closing elements, which in the closed state of the closing system form adhesive connections with the diaper. When producing these closing systems, which have several material layers, for example of non-woven materials, the state of the art forms connection points between the layers by adhesive connections or by welding connections such as ultrasonic welding. The replacement of adhesive connections with welding connections, such as ultrasonic welding, as is disclosed in document EP 2 564 822 B1 for the production of connections between plastic films of diaper closing systems, has the advantage compared with the formation of adhesive connections that used diapers can be easily disposed of because no adhesive materials that compromise the biodegradability are present. Also the risk of damage to the health of the diaper wearer due to toxicity of the adhesive is also avoided, which represents a particular advantage in particular in the case of baby diapers.
The use of the ultrasonic welding process in the case of closing systems in which a support part provided with closing elements is to be connected to an attachment part is problematic in that the heat effect occurring in the welding region on the projecting adhesive closing elements leads to their deformation in the welding region. This deformation is associated with a loss of adhesive force, which compromises the reliability of the diaper closure formed by the closing element. To minimize the loss of adhesive force, one is thus compelled to form only punctiform welding joints, which on the one hand compromises the secure connection between the support part and the attachment part and which is on the other hand complex from a production perspective.